- New public interface: ``repoze.bfg.exceptions.IExceptionResponse``.

  This interface is provided by all internal exception classes (such
  as ``repoze.bfg.exceptions.NotFound`` and
  ``repoze.bfg.exceptions.Forbidden``), instances of which are both
  exception objects and can behave as WSGI response objects.  This
  interface is made public so that exception classes which are also
  valid WSGI response factories can be configured to implement them
  or exception instances which are also or response instances can be
  configured to provide them.

- New API class: ``repoze.bfg.view.AppendSlashNotFoundViewFactory`` (undoes 
  previous custom_notfound_view on request passsed to 
  append_slash_notfound_view).

- Previously, two default view functions were registered at
  Configurator setup (one for ``repoze.bfg.exceptions.NotFound`` named
  ``default_notfound_view`` and one for
  ``repoze.bfg.exceptions.Forbidden`` named
  ``default_forbidden_view``) to render internal exception responses.
  Those default view functions have been removed, replaced with a
  generic default view function which is registered at Configurator
  setup for the ``repoze.bfg.interfaces.IExceptionResponse`` interface
  that simply returns the exception instance; the ``NotFound` and
  ``Forbidden`` classes are now still exception factories but they are
  also response factories which generate instances that implement the
  new ``repoze.bfg.interfaces.IExceptionResponse`` interface.

1 files changed, 17 insertions, 5 deletions

diff --git a/repoze/bfg/interfaces.py b/repoze/bfg/interfaces.py
index def957dad..086c93f3a 100644
--- a/repoze/bfg/interfaces.py
+++ b/repoze/bfg/interfaces.py
@@ -24,6 +24,22 @@ class IWSGIApplicationCreatedEvent(Interface):
     is called."""
     app = Attribute(u"Published application")
 
+class IResponse(Interface): # not an API
+    status = Attribute('WSGI status code of response')
+    headerlist = Attribute('List of response headers')
+    app_iter = Attribute('Iterable representing the response body')
+
+class IException(Interface): # not an API
+    """ An interface representing a generic exception """
+
+class IExceptionResponse(IException, IResponse):
+    """ An interface representing a WSGI response which is also an
+    exception object.  Register an exception view using this interface
+    as a ``context`` to apply the registered view for all exception
+    types raised by :mod:`repoze.bfg` internally
+    (:class:`repoze.bfg.exceptions.NotFound` and
+    :class:`repoze.bfg.exceptions.Forbidden`)."""
+
 # internal interfaces
 
 class IRequest(Interface):
@@ -35,11 +51,6 @@ class IRouteRequest(Interface):
     """ *internal only* interface used as in a utility lookup to find
     route-specific interfaces.  Not an API."""
 
-class IResponse(Interface):
-    status = Attribute('WSGI status code of response')
-    headerlist = Attribute('List of response headers')
-    app_iter = Attribute('Iterable representing the response body')
-
 class IAuthenticationPolicy(Interface):
     """ An object representing a BFG authentication policy. """
     def authenticated_userid(request):
@@ -271,3 +282,4 @@ class ILocaleNegotiator(Interface):
 class ITranslationDirectories(Interface):
     """ A list object representing all known translation directories
     for an application"""
+